A typical endoscope features an elongated tube suitable for introduction into a human or animal body. A lens at a distal tip of the endoscope forms an image of an internal area of the body. Fiber optic cables, wires, or lenses may occupy tubular passages which run the length of the endoscope in order to transmit the image from the internal area of the body at the distal end to an eyepiece or image capturing device at the proximal end.
Gasses, liquids, instruments, or control cables may also pass through passages between the distal and proximal ends. A sheath or other surface usually covers the exterior of the endoscope in order to protect the body from the internal parts of the endoscope, and to protect the endoscope from the environment of the body. Typically the endoscope is air- and water-tight except for the openings of the tubular passages, which may have caps, covers, or valves for sealing the openings when the endoscope is not in use.
Endoscopes are typically washed and sterilized before and after use in medical applications. Endoscopes may be washed by immersion in a liquid such as water or a cleaning fluid, and may be sterilized by immersion in a sterilization fluid or by exposure to a sterilizing gas, which may take place in a reduced pressure environment.
However a typical endoscope having an air- and water-tight structure when capped can be damaged by pressure differentials arising between the interior and the exterior of the endoscope during sterilization. Endoscopes are also routinely transported via air during shipping which can also result in pressure differentials.
In order to address this problem, pressure compensation caps may be provided for covering endoscope openings under these circumstances. Where an air- or water-tight cap or valve would prevent relief of pressure differentials during shipping or sterilization, a compensation cap is configured to equalize the pressure. Pressure compensation caps may have openings which allow liquids and gasses to pass through, and may incorporate valves and/or valve actuators which hold open valves that are integral or assembled with the endoscope.
Typically, pressure compensation caps are designed only for use during storage and shipping of endoscopes, for dry sterilization processing where the endoscope is exposed to a high vacuum, and for gas sterilization where the endoscope is exposed to a sterilizing gas such as ethylene oxide (“ETO”). Separate water resistant caps for endoscopes are available for use with a wet sterilization process.
Routinely however, endoscopes are returned to the manufacturer for evaluation and repair due to fluid ingress. It is suspected that this fluid ingress is due to the end user sterilizing the endoscope using a wet process while leaving the pressure compensation cap in place. This results in needless returns of endoscopes for evaluation and repair.
Water resistant caps often closely resemble a pressure compensation cap. This means that not only are multiple caps required for different sterilization processes and transport, but there is a chance that an end user will mistake one cap for the other, resulting in damage to the endoscope. This damage may be caused either by the fluid ingress described above if a pressure equalization cap is used in a wet sterilization process, or rupture or other damage to the components of the endoscope if a water resistant cap is used in a vacuum sterilization process due to the resulting pressure differential.
It is therefore desired to provide a pressure compensation cap which addresses these deficiencies.